JP2000309776A - Low-voltage blue-emitting phosphor and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-voltage blue-emitting phosphor with an increased luminance and a process for producing the same. SOLUTION: This phosphor comprises a ZnO.Ga2O3 matrix and Bi with which the matrix is doped. The process comprises the steps of: mixing ZnO, Ga2O3, a Bi compound and a flux; subjecting the mixture to the primary firing at 1,100-1,300; milling the substance subjected to the primary firing; washing the milled substance with an acid; subjecting the washed substance to the secondary firing at 800-1,100 deg.C; and classifying the substance subjected to the secondary firing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-voltage blue phosphor and a method of manufacturing the same, and more particularly, to a low-voltage blue phosphor with improved brightness and a method of manufacturing the same.

[0002]

2. Description of the Related Art Vacuum fluorescent display devices and field emission displays (Field Emissi)
As a blue phosphor for a low-voltage driving device such as an on-display device, a ZnS: Zn phosphor is mainly used. Although this phosphor has an excellent initial luminance, it has a problem that its life is short. Therefore, instead of this phosphor, a recent trend is to use an oxide-based phosphor having a slightly lower initial luminance but a longer life and an excellent luminance retention rate.

[0003] Among them, zinc gallate (zinc g)
The phosphor has attracted attention because of its relatively excellent brightness and stable blue color. The zinc-gallate phosphor emits light without using an activator (self-activator).
ion) It is a phosphor.

A method of manufacturing the zinc gallate phosphor will be described with reference to FIG. ZnO, Ga ₂ O ₃ and Li ₃ PO ₄ as a flux are mixed. Next, this mixture is primarily baked at 1200 ° C. in an air atmosphere for about 3 hours. The primary-fired base material (matrix) is milled, preferably ball-milled, whereby the aggregated particles of the base material (matrix) are uniformly dispersed. The particles of the matrix (matrix) dispersed to remove excess Li ₃ PO ₄ are washed with nitric acid. The washed base material (matrix) is secondarily fired at 1100 ° C. in a reducing atmosphere for 1 to 3 hours. Sieve the secondary fired base material (matrix)
To produce a blue phosphor for low voltage.

[0005]

However, since the zinc gallate phosphor does not use an activator, there is a problem that the brightness does not reach a satisfactory level.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a low-voltage blue phosphor with increased luminance. Another object of the present invention is to provide a method for manufacturing the low voltage blue phosphor.

[0007]

In order to solve the above-mentioned problems, the present invention provides a ZnO.Ga
_A blue phosphor for low voltage, comprising: a ₂ O ₃ base material (matrix); and Bi doped into the base material (matrix). As a result, the luminance can be increased. At this time, as described in claim 2, the blue phosphor has x and y coordinates on a CIE color coordinate system of x = 0.20 ± 0.005, y =
It is preferably 0.025 ± 0.005.

According to another aspect of the present invention, as in claim 3, a step of mixing ZnO, Ga ₂ O ₃ , a Bi-based compound and a flux, and the step of mixing the mixture with 1100-1.
First firing at 300 ° C., milling the first fired material, washing the milled material with an acid, and removing the washed material from 800 to 1100.
A method for manufacturing a low-voltage blue phosphor, comprising: performing a second baking at a temperature of about C .; and classifying the second-baked material. The Bi-based compound as claimed in claim 4, can be selected from the group consisting of _Bi 2 _{O 3} and BiCl _3. It is preferable that the amount of the Bi-based compound is 0.001 to 0.1 mol per 1 mol of ZnO.

[0009]

Embodiments of the present invention will be described below in detail. The blue phosphor for low voltage according to the present invention is ZnO
· _Ga 2 _{O 3} comprised Bi to be an activator and the base material (matrix). A method of manufacturing such a low-voltage blue phosphor will be described in detail with reference to FIG.

[0010] ZnO, Ga₂O₃, Bi-based compounds and melts
Mix the agent (flux). At this time, ZnO and Ga₂
O₃Can use the same molar amount. Bi-based compound
The thing is Bi₂O₃Or BiCl₃Can be used
it can. The amount of Bi-based compound used is determined in the later process.
ZnO / Ga₂O₃Base material (matrix) 1 m
0.001 to 0.1 mol% per mole
No. In the present embodiment, ZnO and Ga₂O₃Is the same as
React in the same molar amount to obtain the same molar amount of ZnO.Ga₂O ₃Mother
A material (matrix) is generated. Therefore, Bi
0.001-0.1 mol per mol of ZnO
% Should be used.

The above mixture is primarily fired at 1100 to 1300 ° C. At this time, when the firing process is performed at a temperature of about 1200 ° C. in an air atmosphere, the firing process is performed for about 3 hours. By this firing step, ZnO.Ga ₂ O ₃
A matrix material (matrix) is formed, and Bi penetrates into the matrix material (matrix) and exists in the matrix material (matrix) in a Bi ³⁺ form.

Next, the primary fired product is milled (mi).
ling). Ball mill (ba) for about 3 hours to remove agglomerated particles and improve dispersibility and particle size distribution
It is preferred to carry out (ll-mill).

The milled material is washed with about 0.5N nitric acid or about 1% hydrochloric acid. By this step, an excessive amount of the flux can be removed.

The material washed with nitric acid or hydrochloric acid is 800 to 1
Secondary baking at 100 ° C. At this time, the baking process is preferably performed at about 1100 ° C. for about 2 hours under a reducing atmosphere so as to create an oxygen-deficient atmosphere and contribute to conductivity. This secondary firing step increases the crystallinity of the zinc gallate phosphor and improves the luminous efficiency of the phosphor.

The secondary fired material is sieved (s)
iv) to produce a blue phosphor for low voltage.

The manufactured low-voltage blue phosphor has x and y coordinates of x = 0.20 ± 0.00 on the CIE color coordinate system.
5, y = 0.25 ± 0.05.

The low-voltage fluorescent light produced by the above method.
The body is ZnO.Ga₂O₃With matrix material (matrix)
It is composed of Bi as an active agent. Acts as an activator
Bi on the base material (matrix)³⁺
Exists as an ion at room temperature ³P₁⇒¹Due to S transition
Blue light emitting region. Optical bandwidth (band)
 gap) is 4.4 eV.₂O₄Phosphor
Light emission is Bi³⁺When Bi is added³⁺Is ZnG
a₂O₄Doping inside, so it is not
ZnGa₂O₄Phosphor emission and energy from matrix
-Bi by transmission³⁺Appear due to the emission of light.

The intensity of the blue emission spectrum of the blue phosphor according to the present invention is the intensity of B due to the ³ P ₁ ⇒ ¹ S transition of Bi ^3+.
It changes with i ³⁺ concentration change. Therefore, the maximum emission intensity in the intensity of the blue emission spectrum can be obtained when the probability of self-transition of ZnGa ₂ O ₄ and the probability of energy transfer to Bi ³⁺ ions are high.

The following are preferred to aid in understanding the invention.
An example is provided. However, the following examples illustrate the invention.
It is only provided for easy understanding.
The invention is not limited to the following embodiments.Example 1  1 mol ZnO, Ga₂O₃1 mole, excess Li₃PO₄
And Bi₂O₃After mixing 0.001 mol, atmosphere atmosphere
Primary baking was performed at 1200 ° C. for 3 hours. Fired thing
After performing a ball mill for about 3 hours,
Washed with acid. The acid-washed material is removed under a reducing atmosphere.
Secondary baking was performed at 00 ° C. for 2 hours. Classify the calcined material
To produce a low-voltage blue phosphor.

[0020]Example 2  Bi₂O₃Except that 0.005 mol was used.
It carried out similarly to Example 1.

[0021]Example 3  Bi₂O₃Except that 0.01 mol was used.
Performed as in Example 1.

The VFD (Vacuum Fluorescent) is obtained by using the blue phosphor for low voltage manufactured according to the method of the first to third embodiments and the conventional ZnGa ₂ O ₄ phosphor.
ent Display), and driven at 50V to measure the luminance. Measured luminance of conventional phosphor is 1
Table 1 below shows the relative luminance when converted to 00.

[0023]

[Table 1]

Although the preferred embodiment according to the present invention has been described with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an example. It is clear that a person skilled in the art can conceive various changes or modifications within the scope of the technical idea described in the claims, and it is obvious that the technical scope of the present invention is not limited thereto. It is understood that it belongs to.

[0025]

As described above in detail, according to the present invention, the conventional self-luminous phosphor, ZnGa ₂ O ₄ , is added with a Bi-based compound as an activator, whereby the conventional light-emitting phosphor is activated. Compared with the phosphor, it is possible to provide a low-voltage display device in which the luminance is increased by 15% or more and the luminous efficiency is excellent.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a process of manufacturing a low-voltage blue phosphor according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a process of manufacturing a conventional low-voltage blue phosphor.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H01J 31/12 H01J 31/12 C 31/15 31/15 E (72) Inventor Song Melan Suwon, Gyeonggi-do, Republic of Korea No. 802, 105, Songji Apartment, No. 2

Claims (5)

[Claims] 1. A low-voltage blue phosphor, comprising: a ZnO.Ga ₂ O ₃ host material (matrix); and Bi doped into the host material (matrix). 2. The blue phosphor has x and y coordinates of x = 0.20 ± 0.005, y = 0.5 on a CIE color coordinate system.
2. The low-voltage blue phosphor according to claim 1, wherein the value is 025 ± 0.005. 3. A step of mixing ZnO, Ga ₂ O ₃ , a Bi-based compound and a flux, and mixing the mixture with 1100 to 130.
First firing at 0 ° C., milling the first fired material, washing the milled material with an acid, and second firing the washed material at 800 to 1100 ° C. And a step of classifying the second-fired material. 4. The Bi-based compound is composed of Bi ₂ O ₃ and Bi
Method for producing a low-voltage blue phosphor according to claim 3, characterized in that it is selected from the group consisting of Cl _3. 5. The method according to claim 3, wherein the amount of the Bi-based compound is 0.001 to 0.1 mol per 1 mol of ZnO.